Piston packing



March 29, 1932. A. w. MORTON 1,85l,108

FISTON PACKING Filed March 7, 1931 Snvcntor:

- l l ?marim? v W M m( Ll (ttorncgs Patented M ar. 29, 1932 "UNITEDSTATES PATENT OFFICE AL'LEN 'WMORTONQ OF BALTIMORE, MARYLAND, ASSIGNORTO THE AMERICAN HAM- MERED PISTON RING- COMPANY, 'OF BALTIMORE,MABYLAND, A COBPORATION OF MARYLAND PISTON :meme

Application filed March 7, 1931. Serial No. 520318.

My invention relates to piston packings, and particularly to packingsmade up of a plurality of interfitting rings.

One of the objects of my invention is to produce a packing made up oftwo rings in which radial Leakage of gas pressure through the ringjoints is positively prevented by a novel arrangement of these joints.

Another object of my invention is to provide a rin which is simple tomanufacture and assem le because of the absence of pins or other meansfor preventing rotation of the rings one relatively to the other, and inwhich means of this character are unnecessary because the ring jointsare sealed in all positions and the rings are free to rotate to aposition in which the most perfect cylinder contact is obtained.

Still another object of my invention. is to prod'uce a packing composedof rings of large section adapted tobe forced axially against the sidesof the ring grooves by gas pressure, and in which the rings have broadbearings on the lands of the grooves, thereby reducing groove wear. i

A further object of the invention is to produce a packing in which theinterfitting parts are sealed by the oil which is forced between them bythe pressure within the cylinder.

Other objects will appear from the following specification when read inconnection with the accompanying drawings, in which Fig. 1 is a View,partly in section and partly in elevation, of a piston having mountedtherein packings embodying my invention,

tion of the ring, piston and cylinder wall;

Figs. 5 and 6 are sectional views, similar to Fig. 4, of modified formsof packing; j Figs. 7 to 10 are similar sectional views showing modifiedarrangements of the ring joints. r c

Similar reference characters refer to similar parts'in each of the.several views.

Referring first to Fig. 1, the reference character 11 designates aconventional form of piston, such as is employed in internal combustionengines of the Diesel type. This piston contains annular ring grooves 12havng seated therein packings 13,' which contact with the inner face ofcylinder wall 14. I As here shown, the top three ring grooves containpackings embodying my invention, while thebottom ring groove is shown ascontaining a conventional oil ring 25.

Each of the packings 13 comprises split rings 15 and' 19. Ring 15contains an annular groove 16 cut in ,one side face thereof, the freeends of the ring adjacent the split terminating in legs 17, 17'. Theselegs have inclined faces 18 which meet in a plane intersecting one sideface of the ring and one wall of the groove 16, but the lane ofintersection 18 does not intersect t e inner or outer circumference ofthe ring. The advantage of this arrangement is t at no radial passagewayis formed between the inner and outer faces of the ring; hence, leakageand shown inFigs. 1 and 2, showing the relablow-by to the rear of thering are effectively prevented.

the piston being shown inside of a cylinder to enter and nterfit withthe grpove Fig. 2 is a section on line II.-II of Fig. 1, with thecylinder omitted;

F'ig. 3 is a fragmentary perspective view of one form of ring jointembodying my in: vention, the joint being split apart and certain of theparts being shown in section;

Fig. 4 is an enlarged section of the ring 16 in ring 15. The two ends ofring 19 adja cent the split terminate in two legs 21 and 21', eachhaving an inclined face 22, these faces meeting in a plane whichintersects the one flat side face of ring 19 and the other side face inproximity to the tongue 20. This joint is of the same type as the jointpreviously described in connection with ring 15, and has the sameadvantages.

The manner in which rings 15 and 19 are assembled to form a completepacking will be ob"`vious from an inspection of Figs. 1 to 4, whereinthe ring 19 is seated in the bottom of the ring groove, and ring 15 isplaced on top of ring 19 with the tongue 20 interfitting with the groove16 so that the two rings form a a packing and substantially fill thering groove in an axial direction.

The groove 16 is preferably made of somewhat greater radial width thanthe corresponding radial width of tongue 20 so as to allow the two ringsto move freely in a radial direction, and to produce a tight sealagainst the cylinder wall. When the packing is assembled in this manner,it will be clear that there is no radial path between the inner andouter circumferences of the packing, on account of the tongue and grooveConstruction of the two rings forming the packing and also on account ofthe form of the joints inthe two rings, which do not intersect eitherthe outer or inner circumferences of the rings in the same radial plane.This is true regardless of the circumferential position of either orboth of the rings, and'because of this construction it is unnecessary toprovide any means for preventing relative rotation of the two rings.When a packing of this character is installed in a cylinder which isslightly out of round, the rings are free to rotate and to -take up aposition wherein the most natural and effective cylinder-contactingbearing results.

By reference to the two intermediate grooves in Fig. 1, the position ofthe planes of contact of the faces of the joints in ring 19 and also inring 15 are apparent. Not only do these rings prevent radial leakagebetween the inner and outer faces, but they present broad flatuninterrupted land-engag mg surfaces which minimize wear on the groovelands. They also present pr'actically an uninterruptedcylinder-contacting surface so that compression loss is reduced to aminimum. It will likewise be noted that the cylinder-contacting portionsof these rings are of large cross section so as to withstand long wearwithout any material weakening of the parts, and by placing the tongueand groove near the inner circumference of the packing, the life of thepacking can be considerably lengthened;

When'the packing is installed in a ring groove, the combined axial widthof the two rings may be less than the width of the groove so as to allowgas pressure to enter between the ring and the ring groove and pass bythe packing. In such a case, the subsequentaction of the pressure willbe to force the rngs axially against the sides of the ring groove,thereby rendering the scaling` of the piston more effective andmaintaining such seal as the rings become worn.

This scaling action may be facilitated by' a Construction such as shownin Fig. 5, wherein the inner wall of ring 15 adjacent groove 16 is cutaway for a short distance at 16' and the bottom ring 19 is likewise cutaway adjacent the tongue 20 at 20' so as to aflord a larger surface ofentry for this gas pressure. A similar result may be obtained by merelycutting away a portion of the ring 15, as in Fi 6.

shown in Figs. 1 to 4, the planes of contact of the faces of the ring joints designated 18 and 22 are approximately parallel when the rings areassembled, and the inclination is inward and upward from the peripheryof the packing. In some nstances, it may be desirable to reverse thisinclination, as shown in Fig. 7 in order to make the piston sealmoreeflective.

Fig. 8 shows a further modified form wherein the two planes of contactof faces 18 and 22 are placed form an angle with respect to one another,and' the plane of faces 22 passes through the tongue 20. Likewise, inthis modification the ring 15 is placed in the bottom of the ringgroove, and the ring 19 in the top of the groove.

In Fig. 9, the two 'planes formed by faces 18 and 22 are substantiallyparallel and ring 15 is again shown as being placed in the bottom of thering groove but the plane of faces 22 does not intersect the tongue 20.

Fig. 10 is still another arrangement wherein the planes of faces 18 and22 are angularly disposed to one another and the ring 15 is in thebottom of the groove, but in this case, the plane 22 inclines inwardlyand the plane 18 also inclines inwardly but downwardly from theperiphery of the piston.

I am well aware that in the prior art it is known to make packings of aplurality of split rings which interfit, but I believe that I am thefirst to provide a packing of this character having joints soconstructed as to make it possible to have the two rings freelyrotatable one relative to the other, without altering the eificacy ofthe packing even though the joints in the two rings should line up.

It is to be understood that, although I have herein shown and describedonly a few embodiments of piston packings constructed in accordance withmy invention,'various other arrangements may be adopted and I do notdesire to be limited, except as such limitations are necessarily imposedupon the claims.

What is claimed is 1. A piston packing comprising two split rings eachhaving an -overlapping joint in which the plane of overlap intersectsthe side faces only of the ring, one of .said rings containing anannular groove in one side face and the other a corresponding annulartongue coacting with said groove, and said rings being capable of freerotation one with respect to the other. 2. A piston packing comprising afirst split ring having an annular groove in one of its side faces; asecond split ring having an annular tongue fitting into the groove ofsaid first ring, said rings being capable of free rela- 10 tiverotation, and the planes of joint `over1ap in said rings intersectingthe side faces only of the respective rings.

In testimony whereof I have signed my name to this specification. VALLEN W. MORTON.

